1. Field
One or more embodiments described herein relate to a display device.
2. Description of the Related Art
Various types of flat display devices have been developed. One type, known as an organic light emitting diode display, displays images using an organic light emitting diode (OLED). This diode generates light based on the recombination of electrons and holes in a active layer. OLED displays have fast response speeds, are driven with low power consumption, and have excellent emission efficiency, luminance, and viewing angle. In operation, each OLED emits light of a predetermined luminance corresponding to a data current supplied from a pixel circuit.
An OLED display may be driven using various methods. One method is a digital driving method which controls an on-time of a pixel based on a frame. The frame is divided into a plurality of sub-frames, and a light emitting period of each sub-frame is appropriately set in order to display light of a specific gray scale value. OLED displays have drawbacks, one of which includes luminance non-uniformity generated by voltage drops in a power source voltage. The voltage drops may be caused by various factors including but not limited to an increase in display size and different threshold voltages of each OLED element.